The present invention relates to methods and apparatus for treating incontinence, especially by bladder neck support.
Urinary incontinence is an unfortunately common medical complaint. Many treatments have been suggested. Recently, a relatively minimally invasive technique has become more common, in which a bladder neck and/or urethra is supported by a sling, so that the urethra is partially compressed and/or has a support below it so that during straining and/or bladder/uretheral descent, pressure is applied between the urethra and the sling, thereby closing its lumen.
Benderev et. al, in U.S. Pat. No. 5,836,314 and Brenneman et al, in PCT publication WO 98/19606, the disclosures of which are incorporated herein by reference, describe exemplary procedures for treating incontinence. Two or more bone anchors are attached to the pubic bone. Each anchor is pre-threaded with a suture. Brenneman suggests attaching a sling to the sutures such that when the sutures are pulled tight and knotted, the sling is urged towards the pubic bone. Benderev suggests integrally molding one end of a suture with a xe2x80x9csuture supportxe2x80x9d, which suture support is provided to prevent damage to the urethra by the sutures.
It should be noted that, prior to the introduction of slings, some earlier procedures, for example the Burch procedure and the M.M.K. procedure, used only sutures without a sling to support the bladder neck. Also the, different, needle bladder neck suspension procedure uses only sutures. The disadvantage of these procedures is that the bare sutures can cut into and damage the urethra. In a sling procedure, described below, a mesh or a wide strip of material contacts the urethra instead of sutures, so that the urethra is not damaged.
FIG. 1 is a schematic side cut-through illustration of a pubic region 20 during such a procedure, before the sutures are tightened. In the figure, a sling 32 is located between a vagina 22 and a bladder neck 26 of a bladder 24. The sling is threaded by a plurality of sutures 36, which are attached to a bone anchor 30, in a pubic bone 28.
There are two commonly applied methods of bringing sling 32 to a position between vagina 22 and bladder neck 26. In a first method, an incision is made in the vagina, at an area corresponding to that marked with reference number 34, perpendicular to the figure plane, thereby forming a flap. The sling is inserted into the incision, under the flap, and after the sling is tightened, the incision is closed. In a second method, only a small hole in the vagina lining is made for each inserted bone anchor and a tunnel is formed between the two holes, for insertion of sling 32 therethrough.
This family of suture-sling techniques has several disadvantages:
(a) the suture is an additional element which may be damaged during the procedure or after it;
(b) knotting the sutures (after they are tightened) takes skill and time; additionally, some patients have complained that the sutures cause discomfort during sexual activity, since such sutures typically have sharp edges and are often bulky as the suture may have to be knotted as many as six times to assure patency;
(c) the sutures add some unwanted leeway between the positioning of the anchors and the positioning of the ends of the sling; and
(d) the sutures may damage the sling by cutting through it (older tissue being more susceptible); if the suture enters the sling at multiple points (to reduce strain at the sling-suture joints) the sling may be deformed by the sutures.
U.S. Pat. No. 3,580,313, to McKnight, the disclosure of which is incorporated herein by reference, suggests using the tissue between the urethra and the vagina as a xe2x80x9cslingxe2x80x9d and stapling that tissue to the pubic bone. However, this solution may not be suitable for some patients, such as older patients, as their tissue are usually too weak to provide a suitable support. Also, older tissue is more susceptible to cut-through damage from the staples.
An aspect of some preferred embodiments of the present invention relates to a sutureless method of supporting a bladder neck. In a preferred embodiment of the invention, the bladder neck is supported by a sling, and the sling is directly tacked to a pubic bone, without intermediate sutures. Alternatively or additionally, the sling is directly attached to the bone using other means, for example an adhesive. As used herein xe2x80x9cdirectly attachedxe2x80x9d means attached without an intermediate suture. In many cases, the sling will not be in direct physical contact with the bone. Generally, but not necessarily, there will be only tissue (if any) between the sling and the bone. However, in a preferred embodiment of the invention, there will not be a suture or other implant between the sling and the bone.
It is noted that by not requiring sutures, the previously required step of tightening and tying the sutures is not required.
An aspect of some preferred embodiments of the invention relates to a sling that is preloaded with one or more tacks at one or both ends thereof prior to insertion into a body. In a preferred embodiment of the invention, the pre-loaded sling is mounted on a tacker, for insertion into the body. Alternatively, the sling is not provided as pre-mounted on a tack and is mounted on a tack only after the tack is mounted on a tacker with a protruding tack. Optionally, the mounting of the sling is a two step process, in which the tack is assembled after the sling is mounted on it.
An aspect of some preferred embodiments of the invention relates to tacks with wide heads. In a preferred embodiment of the invention, a tack comprises a shaft and a head, where the head has a maximum extent perpendicular to the shaft, which extent (the width of the head) is considerably greater the shaft diameter. Alternatively or additionally, the width of the head is made considerably greater than a maximum extent of a bone-entering portion of the tack (which is usually wider than the shaft). Thus, the head is larger than the hole formed in the sling by its being tacked and the head can maintain the sling in place. In a preferred embodiment of the invention, the head is substantially circular or polygonal. Alternatively, the head is a bar-shaped beam which is perpendicular to the shaft. As used herein xe2x80x9cconsiderably largerxe2x80x9d means 50%, 100%, 200%, 400% larger or more. Although the head may be large, it is not necessarily solid. Rather, one or more holes may be formed in the head. Optionally, these holes are used for threading the sling through them.
In some preferred embodiments of the invention the head can rotate relative to the shaft.
An aspect of some preferred embodiments of the invention relates to disassembled or deformable tacks, in which a sling may be pierced with a small diameter portion of the tack. The tack is then assembled or deformed, so that the head and/or bone entering portions of the tack have a larger diameter than the piercing portion. In one example, the tack comprises two parts, a head with a shaft portion and a bone-entering portion. The sling is pierced by the shaft portion and then the bone-entering portion is attached to a protruding end of the tack. In another embodiment, the bone-entering portion is maintained at a small diameter until after it pierces the sling, for example by a fin in the shaft receding into a recess formed in the shaft or by the shaft being expandable. In another example, the head is separate from the shaft.
An aspect of some preferred embodiments of the invention relates to an attachment to a bone stapler, which attachment holds a sling in place over a staple-exit portion of the stapler, to enable a standard stapler or a standard bone-anchor inserter to be used for tacking slings in accordance with a preferred embodiment of the invention. In a preferred embodiment of the invention, the type of stapler provided is such that the tip of the staple does not protrude from the stapler, so the sling is preferably maintained in place solely by the attachment. In an alternative embodiment, the tip of the staple does protrude from the stapler and may serve to at least partially hold the sling, while the attachment fixes the orientation of the sling relative to the staple or the attachment. If a two prong staple (or tack) is used, such an attachment may serve solely to keep the sling from slipping off the tip of the staple.
An aspect, of some preferred embodiments of the invention, relates to a tacker which includes two stapling heads, for simultaneous tacking of two sides of a sling. In a preferred embodiment of the invention, the tacker comprises two arms, with a tacking head at the end of each arm. Preferably the angle between the arms is controllable to adapt the tacker for different length slings. In a preferred embodiment of the invention, the sling is pre-mounted on the two heads prior to insertion into the body.
There is thus provided in accordance with a preferred embodiment of the invention, a surgical tack, comprising:
a single shaft formed of a bio-compatible material and having a tip adapted for entering and engaging bone; and
a head mounted on said shaft, said head adapted for engaging a substrate between said head and said bone. Preferably, said shaft is a separate element from said head. Preferably, said head is rotatable relative to said shaft. Alternatively or additionally, said head is mounted in a slot defined at an end of said shaft. Alternatively or additionally, said head is mounted on a narrowing of said shaft.
In a preferred embodiment of the invention, said head comprises only one arm extending substantially perpendicular to said shaft.
In a preferred embodiment of the invention, said head comprises at least two arms extending substantially perpendicular to said shaft. Alternatively, said head comprises at least one arm extending at an angle to said shaft.
In a preferred embodiment of the invention, said head defines a plurality of apertures therethrough. Alternatively or additionally, said head comprises a plurality of protrusions extending in a direction of said tip, which protrusions are adapted for engaging said substrate. Preferably, said protrusions are smooth at a portion thereof where they engage said substrate. Alternatively, said protrusions are pointed at a portion thereof where they engage said substrate.
In a preferred embodiment of the invention, said protrusions extend at least half a thickness of the substrate.
In a preferred embodiment of the invention, the tack comprises at least one fin extending from said shaft, distal from said head, and adapted for engaging said bone after insertion of said shaft into said bone. Preferably, said at least one fin comprises at least two angularly spaced apart fins. Alternatively or additionally, said at least one fin comprises at least two axially spaced apart fins. Alternatively or additionally, said at least one fin comprises a separate element from said shaft. Alternatively, said at least one fin is integrally formed with said shaft.
In a preferred embodiment of the invention, said shaft defines a recess and said at least one fin is adapted for recessing into said defined recess, when force having a vector perpendicular to said shaft is applied to said fin.
In a preferred embodiment of the invention, said at least one fin is mounted on a separate fin element, which is attached to said shaft.
In a preferred embodiment of the invention, said head is roughened at a portion thereof that engages said substrate.
In a preferred embodiment of the invention, said tack comprises an advance-stop on said shaft adjacent said head and separate from said head, such that said advance-stop prevents said head, at portions near said shaft, from touching said bone. Alternatively or additionally, said head has two configurations, one in which it has an substantially large transaxial extent and one in which it has a substantially small transaxial extent.
There is also provided in accordance with a preferred embodiment of the invention, a tack insertion device, comprising:
a xe2x80x9cCxe2x80x9d shaped body;
a handle at one end of said body;
a slotted tack holder at a second end of said body, wherein said slotted tack holder holds a tack pointed towards said handle and wherein said slot is adapted for frictionally engaging a tack.
Preferably, said slotted head is adapted to engage a tack having a multi-arm head. Alternatively or additionally, said slotted head is adapted to engage a tack having an apertured head.
In a preferred embodiment of the invention, said device comprises a second tack holder attached to said body at an offset from said first tack holder. Preferably, said device comprises a selectable offsetting mechanism for setting said offset.
In a preferred embodiment of the invention, said device comprises a safety release mechanism that prevents the release of said tack.
There is also provided in accordance with a preferred embodiment of the invention, a method of preparing a sling combination, comprising:
providing a sling formed of a biocompatible material and having two ends;
mounting said sling on a first tack at a first end of the sling; and
mounting said first tack on a tacking device. Preferably, said method comprises mounting said sling on a second tack at a second end of said sling. Preferably, said method comprises mounting said second tack on said tacking device.
In a preferred embodiment of the invention, said method comprises adjusting an offset between two tacking heads of said tacking device.
In a preferred embodiments of the invention, said method comprises cutting said sling after mounting said first tack on said sling.
In a preferred embodiment of the invention, mounting said sling on said first tack is performed after said tack is mounted on said tacking device. Alternatively, mounting said sling on said first tack is performed before said tack is mounted on said tacking device.
In a preferred embodiment of the invention, the method comprises assembling said first tack after mounting said sling on said first tack. Alternatively, the method comprises assembling said first tack after mounting said first tack on said tacking device.
Preferably, assembling said first tack comprises attaching a head to a shaft of said tack. Alternatively or additionally, assembling said first tack comprises attaching at least one fin to a shaft of said tack.
In a preferred embodiment of the invention, mounting said sling on said tack comprises piercing said sling by said tack. Alternatively, mounting said sling on said tack comprises inserting said tack into a hole in said sling.
In a preferred embodiment of the invention, the method comprises inserting at least a part of said tacking device into a human vagina, after mounting said tack on the tacking device.
There is also provided in accordance with a preferred embodiment of the invention, a kit, comprising:
a sling having a length suitable for bladder neck supporting; and
at least one tack, having a head and a shaft, wherein said head has an extent perpendicular to the shaft, which extent is substantially greater than a diameter of the shaft. Preferably, said sling contains at least one pre-punched aperture. Alternatively or additionally, said sling contains at least two adjacent pre-punched apertures, for setting an effective sling size.
In a preferred embodiment of the invention, said at least one tack comprises at least two tacks. Alternatively or additionally, said sling is reinforced at least at its ends.
There is also provided in accordance with a preferred embodiment of the invention, a kit, comprising:
a sling formed of bio-compatible material and having a length and mechanical properties suitable for bladder neck supporting; and
a clip adapted to hold said sling against a tacking head of at least a particular tacking or stapling device.